I. Field of the Invention
This invention relates generally to tools for refinishing a work piece and more particularly, to an internally mounted end prep tool that can be rapidly set up and used in the field to accurately machine flat or beveled surfaces on pipe flanges, valves, fittings and pipe ends within close tolerance ranges.
II. Discussion of the Prior Art
Portable end prep tools are generally known in the art. Industrial tubing is found in refineries, pipelines, steam plants or the like. End prep tools are used to prepare industrial tubing for welding by cutting, machining and/or beveling the end of the tube. Prior art end prep machines mount or clamp to the inside surface of the work piece with an adjustable mandrel. Mounted on the mandrel is an annular housing supporting a gear ring carrying either one or two tool feed assemblies thereon for orbital and radial movement of the cutting tool relative to the work piece. In the U.S. Pat. No. 4,799,409, a drive mechanism is operatively coupled between the gear ring and the feed tool assembly. The drive means included a gear box assembly having a forward, reverse and neutral position, as well as a mechanism for varying the speed of rotation of the feed screw in the tool slide assembly.
While the prior art end prep lathes are useful for refurbishing work pieces, reliance on tripper mechanisms to advance the cutting tool does not always lead to a true phonographic finish to the work piece. A need therefore exists for an end prep tool that results in safe, rigid and accurate on-site machining. The present invention is an improvement over the prior art by providing a feed tool assembly capable of providing a true photographic finish to a work piece.